I bought a pair of these wellies in March 2012 for my girlfriend. We live in Brazil and so she didn't really need to wear them for a few months until the rains set in.
Obviously wellies aren't worn every day and after relatively light usage over 6 months or so the wellies have split in numerous places; over the toes, by the seams, etc, and are no longer waterproof, and therefore, useless for the required purpose.
Having contacted the seller I have been advised that they have a 6 month defect policy, which we are outside of, and so will not qualify for a refund or replacement.
Obviously this is very disappointing if the seller effectively doesn't consider the quality of their own product to warrant a longer defect policy, so unless you are buying wellies to be used very frequently over a very short period then I would consider looking elsewhere.